How do I use add_to in Class::DBI

Data::Company->table('Companies');
Data::Company->columns(All => qw/CompanyId Name Url/);
Data::Company->has_many(offers => 'Data::Offer'=>'CompanyId'); # =>'CompanyId'

Data::Offer->table('Offers');
Data::Offer->columns(All => qw/OfferId CompanyId MonthlyPrice/);
Data::Offer->has_a(company => 'Data::Company'=>'CompanyId');

my $company = Data::Company->insert({ Name => 'Test', Url => 'http://url' });
my $offer = $company->add_to_offers({  MonthlyPrice => 100 });

Can't locate object method "add_to_offers" via package "Data::Company"